NEW LOWER CRETACEOUS CALCAREOUS NANNOFOSSIL SPECIES FROM ENGLAND
Katharina Perch-Nielsen
17 Orchard Rise, Richmond, Surrey TW10 5BX, UK
During an investigation of calcareous nannofossi ls from the boreal
Lower Cretaceous, several new species and a new genus were found which aredescribed below. The zonal scheme proposed by JAKUBOWSKI <1987) for the
Moray Firth area of the North Sea <NLK-Zones) is used for the ageassignment of the samples.
Genus Ceratollthina MARTINI, 1967
Since the introduction· of the genus Ceratol 1 thina from the Middle
Albian minimus layers in NW Germany by MARTINI <1967), it has hardly beenrecorded by others. Its generotype, Ceratol ithina hamata, possesses a welldeveloped apical spur and two horns of different length and curvature <Pl.
1, Figs. 1, 2). The light microscope study of samples from Copt Point
collected during the INA field-trip in 1987 <GALE et al., 1987) yielded
two new species of the genus, C. bicornuta and C. cruxii. The latter might
be considered the ancestor of C. hamata.
Ceratolithlna blcornuta n. sp.
P l . 1 , F i gs . 3 , 4 .
Holotype: Pl. 1, Fig. 3.
Type level: Middle Albian; NLK 4B, Watznaueria barnesae Subzone.
Type locality: Copt Point, Folkestone, SE England; Bed VII.
Derivation of name: bicornuta, Latin for "with two horns".
Diagnosis: Species of Ceratolithina with two apical spurs and horns.
Description: C. blcornuta has two apical spurs of varying length andtwo horns of varying length and curvature. In some specimens, one hornis short and straight and the other longer and curved, in others both
spurs and horns are of about equal length, run parallel and areconnected by a bridge. Their ends are tapering or blunt.
Remarks: Between crossed nico.ls,
flat lying specimens appear brightwhen ·oriented at 0", to the nicols.
Occurrence: Beds VI-VIII at Copt Point ; Middle Albian NLK 4B Subzone.
Ceratollthlna cruxli.n.sp.
Pl. 1 , Figs. 5-7
Holotype: Pl. 1 , Fig. 5.
Type level: Middle Albian; niobe ammonite Zone; NLK 4B, Watznaueria
barnesae Subzone.
Type locality: Copt Point, Folkestone, SE England; Bed VII.
Derivation of name: After J.A. CRUX, nannofossil specialist with BP.
Diagnosis: Calcareous nannofossi l with a straight to very slightly
curved horn and one or several lateral blade(s).
Description: The straight to slightly curved rod has one to several
blades. The form of the blades varies greatly from sickle-like to
sai 1-shaped. The rod is yellow when oriented at 0''' to the crossed
nicols, while the thin blade only reaches grey.
Remarks: This form is tentatively assigned to Ceratolithina, since it
occurs with and just below C. hamata in the Middle Albian at Copt
Point and may be the ancestor of that species. Moreover, there is no.
better suited published genus available. It is unlikely that C. cruxii
is related to the genus Lithraphidites which has a cruciform crosssect ion.
Occurrence: Beds I-IX at Copt Point; Middle Albian NLK 4B Subzone.

30

INA Newsletter vol.10- 1988

Kokla n. gen.
Generotype: Kokia borealis
Derivation of name: After C. P. KOK, micropaleontologist with Shell.
Diagnosis: Flat to thick rosette-shaped body with more than 6 segments
or rays and faint to strong birefringence.
Description: The proportion of the free ends of the segments or raysvaries from none to ea. 2/3. Their ends are blunt or tapering. The
sutures between the segments are straight or curved and there is nocentral hole. Very flat specimens show only weak birefringence while
thicker ones are stronly birefringent.
Remarks: KOK <1985) illustrated and described a flat calcareous
nannofossi l as UFO 2 from the "Valanginian of the North Sea". This
form, here named Kokia borealis, was since found by several colleagues
in many other wells. The very big specimens of Kokia are somewhat
similar to Biantholithus sparsus from the Danian. The latter isusually smaller and thicker than Kokia specimens and the number ofsegments varies in the same assemblage, while it stays the same in
Kokia. Rucinol i thus includes "calcareous nannofossi ls that have theappearance of a rosette of 5 or more inclined segments in plan view".
In Kokia, the segments are not inclined.
Other species include Kokia sp.
which occurs in the Hauterivian of
Speeton and Kokia curvata from the Valanginian of the North Sea.

Kokia borealis
Pl. 1, Figs. 8-10
Holotype: Pl. 1, Fig. 8.
Type level: Upper Berriasian; NLK 19A, Sollasites arcuatus Subzone.
Type locality: Central North Sea; Shell/Esso Well 22/21-2.
Derivation of name: from boreal = northern.
Diagnosis: Flat body with 8 tapering rays which are free for about 1/4
or more of their length.
Description: K. borealis has 8 tapering to blunt rays. The free length
can vary from about 1/4 to 1/2 of the total length of the rays. The
sutures between the rays are more or less radial and straight. K.
boreal is appears in different shades of grey between crossed nicols
and the rays become extinct in turn when the slide is rotated.
Remarks: K. boreal is differs from K. curvata which often is thicker,
by its longer free rays and the usually straight sutures between them.
It differs from Kokia sp. by having only 8 rays against the latter's
10.
Occurrence: KOK <1985) had assigned a Valanginian age to the samples
containing his UFO 2 from the North Sea. It can now be assumed thatthe samples including K. bon~alis are of Berriasian age, since theyoccur with or below Sollasites arcuatus, which seems to be restricted
to the upper part of the Upper Berriasian <JAKUBOWSKI, 1987; CRUX.
1987). K. boreal is was found in the Central and in the Northern North
Sea.
P l.

Kokia curvata
1 , Figs. 11-13

Ho I o type: P l . 1 , F i g . 11 .
Type level: Lower Valanginian; NLK 18 Zone.
Type locality: Northern North Sea; Shell/Esso Well 211/13-7.
Derivation of name: from.curvata, Latin for curved.
Diagnosis: Flat body with 8 segments, of which less than 1/4 is free.
The sutures between segments are curved and their tips are rounded.
Desct~ipt1on:}(, curvata is gr-ey to yellow between ct-ossed nicols,

INA Newsletter vol.lO- 198831

depending on its thickness. Overgrowth often fills in the space
between the ray-tips and obscures the sutures which, however, may
still be recognised by careful focussing and by the overlap of therays producing an inner rosette-shaped pattern <Pl. 1, Fig. 11).
Remarks: The curved sutures and the short free part of the rays
distinguishes this species from the other species in the genus. Large
specimens of Micrantholithus sp.
can look similar but can be
distinguished by their 5 instead of 4 or 8 units as in K. curvata.
Occurrence:K.
curva ta was
foundtogether with and below M.
speetonensis in the Lower Valanginian <and Upper Berriasian ?) of theNorth Sea. The "calcite rosettes" of AARHUS et al. <1986) may in part
represent K. curvata.

Kokfa sp. 1
Pl. 1, Fig. 14
Big specimen of Kokia consisting of 10 segments with tapering ends andcurved sutures. The free ends of the 10 segments are less than 1/2 thetotal length of the segments and pointed to blunt. The sutures between thesegments are strongly curved. Kok la sp. 1 has more segments and is bigger
than K. boreal is and K. curvata. It was only found insample from
Speeton, labelled "base of bed C2". This bed is generally assumed to be of
Late Hauterivian age, but contains calcareous nannofossi ls of the upper
Lower Hauterivian, without Tegulalithus septentrionalis and Eprolithusaantiquus.

Genus Mfcrantholfthus DEFLANDRE 1954
obtusus are often a common partof the lower Lower Cretaceous assemblages in the North Sea. Besides these
forms there occur rare Braarudosphaera regularis and B. africana and rare
to common
M. speetonensis, M. brevis and M. lamberti 1, a new species
described below.
Micrantholithus hoschulzii and/or M.

Mfcrantholfthus lambertfi
P 1 . 1 , Figs. 17, 18
Holotype: Pl. 1, Fig. 17.
Type ·level: Upper Hauterivian; NLK 16A, Speetonia colligata Subzone.
Type local fty: Central North Sea; Shell/Esse Well 30/ 11B-1.
Derivation of name: After B. LAMBERT, micropaleontologist with TOTAL,France.
Diagnosis:

Species of Micrantholithus with long thorns on 4 of the 5

segments.
Description: M. lambertii has one segment like M. hoschulzii or a
Braarudosphaera regularis, while the other 4 segments have an elongate

thorn each along the sutures. The thorns are arranged in pairs.
M. lambertii differs from other species of the genus by its
unequal development of the segments of the pen tal i ths. Broken single
segments constitute an unusual sight in some samples and can be quite
common.
LAMBERT <1986) i 11 ustrated beautifully an Upper Al bian coccosphereof Braarudosphaera afr i can a with pent a 1 i ths belonging to different"species". It is possible that also M. lambertii should be assigned toM. obtusus/M. hoschulzii or Braarudosphaera regularis, the species
with which it eo-occurs. But the occurrence of M. lambert 11 over only
a few mi 11 ion years in several wells in the North Sea suggests its.
spatial and temporal separation from the other species which occur
intermittently over most of the Lower Cretaceous in this region.
Occur-rence: Upper Valang1n1an to Upper Hauterivian of the North Sea.
Remarks:32

INA Newsletter vol.10- 1988

Genus Nannoconus KAMPTNER, 1931
Well known Tethyan nannoconids such as N. steinmannii, N. kamptneri, N.
globulus, N. truittii and N. bermudezii , but also 'some new species of
Nannoconus have been found in the Lower Cretaceous of the North Sea. In
their description, the width of the row of wedges <PERCH-NIELSEN, 1~85:377) is mentioned. Thin wedges of about 0. 5 ('J-m thickness are found in N.
abundans and N. concavus. Medium-sized wedges measure about 1 l.tm and areseen in most nannoconids such as N. steinmannii, N. kamptneri and here in
N. alvus, N. longus and N. dislocatus. Thick, coarse wedges are thicker
than 1.5 Mm and are found in N. oviformis and in N. sabinae. One can also
observe different angles of the wedges to the central canal: right angle
to flat in N. abundans, N. concavus, N. sabinae and N. alvus; low angle ofabout 1030"' in most nannoconids and here in N. 1ongus and N.
dislocatus; high angle of about 30 - 60"' as here in N. oviformis; a steep
angle of more than 60° has been observed in very rare nondescribed forms.
Nannoconus alvus
Pl. 1, Figs. 19,20
Holotype: Pl. 1, Figs. 19,20.
Type level: Upper Berriasian; NLK 19A, Sollasites arcuatus Subzone.
Type locality: Central North Sea; Shell/Esse Well 29/7-1.
Derivation of name: From alvus, Latin for beehive.
Diagnosis: Beehive-shaped species of Nannoconus with no or a very
narrow central canal and medium size, very low angle, rows of we~ges.
Description: N. alvus is wider than high in side view. It has aconcave base, more or less vertical sides and a dome-shaped apicalpart. The rows of wedges are of medium width and lie relatively flat.
Remarks: N. alvus probably often lies flat and then appears as a thickdisc. Separate discs are common and can not be distinguished fromseparate discs of other species.
Occurrence: Upper Berriasian of the Central North Sea.

Nannoconus concavus
P l. 1 , Figs. 2 1-2 4Holotype: Pl. 1, Fig. 22.
Type level: Upper Berriasian; NLK 19, Nannoconus steinmannii Zone.
Type locality: Central North Sea; Shell/Esse Well 29/7-1.
Derivation of name: From concavus, Latin for concave.
Diagnosis: Species of Nannoconus with concave sides and apex and flat
to concave basal part. Central canal about 1/3 or less of the width in
the central part. Thin, flat rows of wedges.
Description: The outline of N. concavus in side-view is concave at thesides and in the apical part, while the basal part seems flat toslightly concave. The central canal comprises
about 1/3 or less of
the width of the body at the middle. The height of N. concavus ranges
from slightly shorter than wide to slightly higher than wide. The
species has a crenulate outline in top-view <Pl. 1, Fig. 24-). The
wedges are thin and relatively flat lying to low-angle to the central
canal.
Remarks: N. concavus has not as wide a central cavity as N. quadratus<Pl. 1, Fig. 25), a similar Tethyan species, which has more ruggedly
concave sides and also occurs in the North Sea. N. abundans often haslarger apical discs and has even thinner wedges than N. concavus. It
has usually a narrower central canal. In top view it can only be
distinguished from N.. concavus in , when it features remnants of thewider apical discs.

INA Newsletter vol.lO- 1988

33

Occurrence: Upper_ Berriasian and lowermost Valanginian of the North
Sea, where it does not overlap with M. speetonensis.
Nannoconus dislocatus
P l . 1 , Figs. 2 6, 2 7Holotype: Pl. 1, Figs. 26, 27.
Type level: Lower
Hauterivian; NLK 17, upper part of Corollithion
silvaradion Zone.
Type locality: Northern North Sea; Shell/Esso Well 211/29-8.
Derivation of name: From dislocatus, Latin for displaced.
Diagnosis: Elongate species of Nannoconus consisting of two parts thatare offset relative to one anotherand a relatively wide central canal.
Medium-sized, low angle rows of wedges.
Description: This cylindrical species is higher than wide and consistsof an oblique basal part and a slightly dislocated apical part. The
central canal is about as wide as the walls and hasa kinkapproximately in the middle. The rows of wedges are of medium widthand form a low angle to the central canal.
Remarks: N. dislocatus differs from N. kamptneri, which also has arelatively wide central canal, by its obli,queness and the kink in the
middle of the formers central canal.
Occurrence: Hauterivian of the Northern North Sea.
Nannoconus longus
Pl. 1, Figs. 34-,35Holotype: Pl. 1, Fig. 35.
Type level: Upper Barremian; NLK 11, Nannoconus borealis Zone.
Type locality: Central North Sea; Shell/Esso Well 22/26A-2.
Derivation of name: From longus, Latin for long.
Diagnosis: Very long species of Nannoconus with a total length morethan two times the maximum width. Bulbous at the apex. Central canalabout 1/3 of width. Medium-size, low angle rows of wedges.
Description: N. longus has one bulbous and one open end. The thick end
is only slightly wider than the long, slightly flaring or parallelsided body. The central canal is about as wide as the wall, which isbuilt of wedges of medium width. There is no cavity in the bulbous
part.
Remarks: N. longus is longer than most other species of Nannoconus andis the only species with a bulbous apex and a length to width ratio
more than two as found in N. borealis. N. boletus and f'l. bonetii areshorter, N. dauvillieri has a flaring rather than bulbous apex, N.
kamptneri has no distinct bulbous apex and N. steinmannii has a very
narrow central canal and no bulbous apex.
Occurrrence: Upper Barremian of the North Sea.

Hannoconus oviforais
P l . 1 , Figs. 32, 33
Holotype: Pl. 1, Figs. 32, 33.
Type level: Upper Berriasian; NLK 19A, Sollasites arcuatus Subzone.
Type locality: Central North Sea; Shell/Esso Well 29/7-1.
Derivation of name: From ovum, Latin for egg, and forma, Latin forshape.
Diagnosis: Large, ovoid species of Nannoconus with wide central cavity
and few, thick rows of wedges at a high angle to the central canal.
Description: N. oviformis has an oval outline in side-view and is
subcircular in apical view. The wall is of equal thickness over mostof the body end built of few rows of wedges surrounding a wide central

INA Newsletter vol.10- 1988

34

cavity.
Remarks: N. oviformis is bigger than N. globulus and has thicker,
steeper rows of wedges than that species.
Occurrence: Upper Berriasian of the North Sea.
Nannoconus sabinae
Pl. 1, Figs. 28-31
Holotype: Pl. 1, Figs. 28, 29.
Type level: Upper
Berriasian; Nannoconus sp. (discs) Zone of CRUX
<1987).
Type locality: Central North Sea; Shell/Esso Well 29/7-1.
Derivation of name: After Sabine, my youngest daughter.
Diagnosis: Flat to high species of Nannoconus consisting of parallel
lying wedges consisting of very thin parallel lying tiers and withouta central canal.
Description: The holotype consists of 3 layers of wedges arranged
parallel rather than spirally as usual in Nannoconus. In side-view, up
to 8 layers of wedges have been seen <Pl. 1, Fig. 30), but specimens
with fewer tiers are more common. Each wedge, in turn, consists ofnumerous very thin, slightly undulating tiers. No central canal isvisible.
Often, N. sabinae is seen in apical view and then appears,
depending on its thicknes, as faintly to strongly birefringent, large
disc. The sutures are arranged radially in the single discs or rows of
wedges.
Remarks: The assignment of this species to Nannoconus is not totallyconvincing, since typical representatives of Nannoconus have the rowsof wedges arranged in a spiral rather than horizontally.
Large nannoconid discs were already mentioned from the Berriasianby JAKUBOWSKI <1987) in his Zone NLK 19 and CRUX <1987) based a zone
on their range below the range of Sollasites arcuatus. They probably
represent the single layers of N. sabinae.
Occurrence: Upper Berriasian of the North Sea and Speeton.

Genus Trlquetrorhabdulus MARTINI 1965
The genus Triquetrorhabdulus includes calcareous rods with a triradial
cross-section and occurs from the late Late 01 igocene through the Late
Miocene. Similar forms are also in the Lower Cretaceous.
Trlquetrorhabdulus? shetlandensis
Pl. 1, Figs. 15, 16
Holotype: Pl. 1, Fig. 16.
Type level: Lower Valanginian; NLK 18, Micranthol ithus speetonensis
Zone.
Type locality: Northern North Sea; Shell/Esso Well 211/13-7.
Derivation of name: From the East Shetland Basin, where the well issituated.
Diagnosis: Elongate to diamond-shaped hody withtriradiate crosssect ion.
Description: T.? shetlandensis has 3 blades which are usually widest
towards about 1/4 to 1/3 of the length from the blunter end of the
body. The 3 blades are not always equally well developed. The one
standing vertically reaches blue birefringence colours at 45° between
crossed nicols. The specimens are dark when oriented parallel to thecrossed nicols.
Remarks: Although T.? shetlandensis most likely is not related to the
Oligocene/Miocene genus Triquetrorhabdulus, it is tentatively includedin this genus, since it seems even more unlikely that it is related to

INA Newsletter vol.10- 198835

the Eocene genus Pseudotriquetrorhabdulus which consists of up to
eight laths, or the Cretaceous genus Lithraphidites which has acruc if or m cross-sect ion.
The Upper Jurassic Pseudoli thraphi ditesconsists of 4 or 6 circular rods.
Occurrence: Lower Valanginian through Lower Hauterivian in Speeton and
the North Sea.
ACKNOWLEDGMENTS
I thank Ben Prins <Shell, The Hague) and Shirley van Heck and Wytse
Sikkema <Shell, London) for constructive remarks and Shell Expro UK for
permission to publish and for providing copies of the colour plate.
REFERENCES
Further pre-1986 references and the authors of the species mentioned
can be found in PERCH-NIELSEN, 1985.
AARHUS, N,, VERDENIIJS, J, & BIRKELUND, T,, 1986, Biostratigraphy of a L•Jwer Ci•eta•:e•Jus
section from Sk 1i nnabanken, No1•way, with some comments •J11 the Andtya e:<posu!'e, N•Jrsk Geol,
tidskr,, 66: 17-4:3,
CRUX, J,A,, 1987, Bo1'eal Eal'ly Cretaceous nannofossil biostrati·~1·aphy CRyazanianBarremian), INA Newsletter, 9/2: 48,
GALE, A,S,, WARD, D,J, & CRUX, J,A,, 1987, The Cretaceous and Palaeoce11e of East Kent- a
field guide, INA Newsletter 9/2:65-72,
JAKUBOWSKI, M,, 1987, A proposed Lower Cretaceous calcareous nannofossil zonation scheme for
the Moray Firth Area of the North Sea, Abh, Geol, 8,-A, 39: 99-119,
KOK, C,P,, 1985, UFO 2: An Ea1·ly Cretaceous nannofossil fr•Jm the Cent1•al North Sea, INA
Newsletter 7:34, 35, 38,
LAMBERT, 8,, 1986, La Mtion d'esp~·:e chez le gen1·e Braarud..,sphat?ra Defland!'e, 1947, Mytheet realite, Revue de Micropal,, 28/4: 255-264,
MARTINI, E,, 1967, Ct?ratolithina hamata n,gen,, n,sp,, aus dem Alb V•Jn NDeutschland
CNannoplankton, incertae sedis), N, Jb, Geol, Palaeont, Abh,, 128: 294-298,
PERCH-NIELSEN, K,, 1985, Mesozoic cal•:areous nannof•Jssils, In: Bolli, H,M, et al,, eds,:
Plankton Stratigraphy: 329-426, Cambridge University Press, Cambridge,

PLATE 1
Magnification ea. 1800x; x-nicols withindicated by 0 in upper left corner of figures.
Figs 1,2
Figs 3,4
Figs 5-7
Figs 8-10
Figs 11-13
Fig. 14
Figs 15, 16
Figs 17, 18
Figs 19,20
Figs 21-23
Fig. 24
Fig. 25
Figs 26,27
Figs 28-30
Fig. 31
Figs 32,33
Figs 34,35

Ceratolithina hamata
Ceratolithina bicornuta
Ceratolithina cruxii
Kokia borealis
Kok i a curva ta
Kokia sp. 1
Tr i que trorhabdul us? she t 1andensis
Micrantholithus lambertii
Nannoconus alvus
Nannoconus concavus
Nannoconus concavus
Nannoconus quadratus
Nannoconus dislocatus
Nannoconus sabinae
Nannoconus sabinae
Nannoconus oviformis
Nannoconus longus

INA Newsletter vol.10- 1988

gypsum plate;holotypes

Copt Point 13
Copt Point 12
Copt Point 12,12,8
Shell/Esse 22/21-2
Shell/Esse 211/13-7
Speeton, C2; RP 13
Shell/Esso 211/13-7
Shell/Esso 30/llb-1
Shell/Esso 29/7-1
Shell/Esse 29/7-1
Shell/Esse 30/6-3
Shell/Esse 29/7-1
Shell/Esse 211/29-8
Shell/Esse 29/7-1
Shell/Esso 211/29-8
Shell/Esse 29/7-1
Shell/Esso 22/26-A2

Plate 1

Ceratolithina hamata Ceratolithina bicornuta Ceratolithina cruxii

Kokia curvata

Nannoconus sabinae

N. sabinae

Nannoconus oviformis

Nannoconus longus